OZstamps -

UA also now has an yellow F equivalent (says "United First") to the orange priority tags that are much more visible than the old bruise colored flags.

It was explained to me that part of the reason they changed systems with the priority tags is that many, many people just left the old elastic F tags on their bags and received priority handling when they weren't flying F. With this system, it's not possible to reuse them, as they (as you point out) come off easily over the course of a trip, or when the agent puts on a new bag check tag.

Greg